/Engine/Source/Runtime/Slate/Public/Framework/MultiBox/MultiBoxBuilder.h
Adds a menu entry with a custom widget
void AddMenuEntry ( const [FUIAction](API\Runtime\Slate\Framework\Commands\FUIAction) & UIAction, const [TSharedRef](API\Runtime\Core\Templates\TSharedRef)< [SWidget](API\Runtime\SlateCore\Widgets\SWidget) > Contents, const [FName](API\Runtime\Core\UObject\FName) & InExtensionHook, const [TAttribute](API\Runtime\Core\Misc\TAttribute)< [FText](API\Runtime\Core\Internationalization\FText) > & InToolTip, const EUserInterfaceActionType UserInterfaceActionType, [FName](API\Runtime\Core\UObject\FName) InTutorialHighlightName )